And it's already been explained that that's not what is happening
Yes, it is.
Okay, I got out of bed and booted up the game just for you, so pay attention.
https://imgur.com/a/uzuToZsThese are an example of when you miss, but hit with RA. The tooltip comes up because you're going to miss, you can check the roll to see how the dice were added up in the tooltip. Which, as I've explained, ONLY happens if that roll will miss. THEN, the second roll hits, deals damage, and you can check the combat log for how the roll was added up for the Advantage roll, which it tells you it was advantage.
https://imgur.com/a/3CBUwDxAnd THESE are when you miss both times, with a low roll first then a high roll, then the high roll first, which is used for the attack and tells you the roll was at Advantage. If the second roll had been higher, it would have showed. The combat log cuts out the middle man and just keeps the first roll because it was the highest.